Controlled release agents have been used in the art in a variety of applications, including the release of pheromones, insect repellents, animal repellents and pharmaceuticals.
For example, U.S. Pat. No. 4,469,613 discloses a detergent bar to release insect repellents which contain poly(.epsilon.-caprolactone) homopolymers and other polymers (e.g. polyethylene or polypropylene). U.S. Pat. No. 5,150,722 discloses a low density polyethylene/high density polyethylene copolymer for use in controlled release. Controlled release in the system described therein is affected by the use of a layered structure, with a core containing the agent to be released and a "burst layer" which confines the active substance from being prematurely released.
U.S. Pat. No. 5,316,744 discloses porous particles for controlled release of an active substance. The particles are blocked by use of a cross-linked hydrogel polymer, the blocking agent being sensitive to its physical environment.
Japanese Patent Publication No. 05 345 011 discloses hydrogenated block copolymers of aromatic vinyl compounds as carriers for fragrances, such as room deodorizers.
U.S. Pat. No. 5,221,534 discloses gels comprising a mineral oil and blends of copolymers and including health and beauty aid components.
PCT Patent Application No. WO88/00603 of Francis et al. describes block copolymer compositions which are described as gels or gelloid liquid extended polymer compositions which comprise an intimate mixture of a block copolymer containing relatively hard blocks and relatively elastomeric blocks. A suitable block copolymer is Kraton 1651, a triblock copolymer. The copolymer additionally contains at least 500 parts by weight of extender liquid per 100 parts of the block copolymer, the liquid being present to extend and soften the elastomeric blocks of the block copolymer.
European Patent Application No. 224389 of Gamarra et al. discloses styrene-diene block copolymer compositions and in particular a mixture of triblock copolymers and a hydrocarbon oil. These compositions are useful as sealing materials.
U.S. Pat. No. 4,369,284 describes a transparent gel prepared from triblock copolymers and oils useful as molded products. The triblock copolymers used therein receive specific styrene end blocks to ethylene and butylene center blocks. The end block to center block ratio is given as being between 31:69 and 40:60.
The present invention provides an improved controlled release air care product using unique vehicle systems.